With many mobile network protocols having been commercialized, it's common that one cell is covered with multiple network signals, where different Mobile Network Operators compete fiercely, and brings more choices for subscribers.
In order to facilitate subscribers choosing mobile network flexibly according to their own needs, most user equipments have multi-card functions.
Currently, most multi-card user equipments can only provide service for one subscriber identity card at one moment. In other words, the existing multi-card user equipments can't provide services for multiple subscriber identity cards at a same time, which does not meet service need of subscribers.
In order to meet the subscribers' service need, a multi-card user equipment which can provide services for multiple subscriber identity cards at a same time emerges. However, hardware cost and complexity of this kind of user equipment is high, and it also occupies too much radio transmission resources.